7. Extensors of the forearm I.
Superficial layer:
brachioradialis m. ext. carpi radialis longus et
brevis mm.
ext. digitorum et ext.
digiti minimi
ext. carpi ulnaris
8. Extensors of the forearm II.
Deep layer:
abductor pollicis longus extensor pollicis extensor indicis
supinator
10. Tendon sheathes of the extensor
muscles
6 compartments:
1.) abductor pollicis longus+extensor
pollicis brevis mm.
2.) ext. carpi radialis longus and brevis
3.) ext. pollicis longus
4.) ext. digitorum+ext. indicis
5.) ext. digiti minimi
6.) ext. carpi ulnaris
11. BLOOD SUPPLY OF THE UPPER LIMB
ARTERIES OF THE UPPER LIMB
THE AXILLARY ARTERY:
This vessel begins at the outer border of the first rib as a continuation of
the subclavian artery and ends at the lower border of the teres major muscle,
where it is passed into the arm as the brachial artery.
The axilary artery supplies the integuments of the shoulder.
THE BRACHIAL ARTERY:
This artery provides the main arterial supply to the arm.
It begins at the lower border of the teres major muscle
as the continuation of the axillary artery. It runs downward and slightly
laterally to the cubital fossa. Where it is divided into its two terminal branches,
the radial and the ulnar artery.
THE PULSE OF THE BRACHIAL ARTERY:
Is palpable on the anterior aspect of the elbow. With the use of stetoscope
and blood pressure cuff often used to measure the blood pressure.
12. RADIAL ARTERY:
It begins in the cubital fossa. This artery passes along the radial side of the forearm
to the wrist. The radial artery leaves the forearm by winding around the distal end
of the radius and passing posteriorly, then it pierces the first interosseal
space and reaches the palmar side of the hand to form a deep palmar branch
with the deep branch of the ulnar artery.
THE RADIAL PULSE
The common place for taking the pulse is where the radial artery lies on the anterior surface of
the distal end of the radius. In this region this artery is covered only by deep and superficial
fasciae and skin. About two fingerbreadths of this artery can be compressed against the distal
end of the radius.
13. ULNAR ARTERY:
It is the larger of the two terminal branches of the brachial artery. It passes from the
cubital fossa along the ulnar side of the forearm to the wrist. At the palmar side
of the hand the ulnar artery forms a superficial palmar arch with the superficial
little branch of the radial artery. The radial and the ulnar arteries supply the elbow
joint, the forearm and the hand muscles as well as the joints of the hand.
PALMAR ARCHES:
It is formed by the radial and ulnar artery at the palmar side of the hand.
They supply the superficial and the deep layers of the hand.
THE DORSAL CARPAL ARCH:
The dorsal carpal arch is an anatomical term for the anastomoses
of the dorsal carpal branch of the radial and the ulnar artery
near the back of the wrist. It anastomoses with the deep palmar arch
15. VEINS OF THE UPPER LIMB
The veins of the upper limb are divided into two sets:
1. Superficial
2. Deep.
1. THE SUPERFICIAL VEINS:
Are principally situated on the dorsal surface of the hand. They form plexuses.
The inner plexus is formed by the veins from the little finger, the outer plexus is
formed by the veins from the thumb. These two plexuses communicate on
the back of the hand forming a superficial arch of veins. The superficial veins
of the palm of the hand form a plexus in front of the wrist.
Basilic vein: formed by the ulnar veins, it passes upward along the
inner side of the forearm and enters into the brachial vein.
Cephalic vein: arises from the radial veins, ascending at the radial
side of the upper limb and terminates into the axillary vein just below the
clavicle. It communicates with the basilic vein via the median cubital vein
at the elbow. The cephalic vein is often visible through the skin.
Medial cubital vein: it is located in the cubital fossa and connects the basilic
and cephalic veins. It is often used for venipuncture (taking blood),
17. 3. BRACHIAL VEINS:
The radial and the ulnar vein unite to form these veins. At the inferior border
of the teres major muscle the brachial veins join to the cephalic vein
to form the axillary vein.
3. AXILLARY VEIN:
It is a large venous blood vessel that conveys the blood from the thorax,
armpit (axilla) and the upper limb toward the heart.
It is a continuation of the brachial veins.
There is only one axillary vein on each side of the body.
18. INNERVATION OF THE UPPER LIMB
BRACHIAL PLEXUS (PLEXUS BRACHIALIS)
The brachial plexus is formed by the union of the anterior divisions of the four lower cervical (C5-C8)
and the first thoracal nerve (Th1). This network of nerves extends from the neck
to the axilla, and supplies motoric, sensory nerve fibers to the upper limb.
1. The C5-C6 unite to form an upper (superior) trunk
2. The C7 continues as a middle trunk
3. The C8- Th1 form the lower (inferior) trunk.
The upper and middle trunks unite to form the lateral cord
The lower trunk continues as the medial cord
The three trunks form the posterior cord.
19. 1. THE LATERAL CORD:
Divides into the musculocutaneous nerve and the lateral root of the median nerve.
THE MUSCULOCUTANEOUS NERVE:
Supplying the muscles of the front of the arm
The endbranch of the musculocutaneus nerve is called as the lateral cutaneous nerve of the
forearm, which becames superficial and supplies the skin on the lateral aspects of the forearm.
THE LATERAL ROOT OF THE MEDIAN NERVE:
It is the continuation of the lateral cord. It is joined by the medial root of the
median nerve to form the median nerve.
20. 2. THE MEDIAL CORD:
• THE MEDIAN NERV:
Is formed by a lateral and a medial root. This nerve passes inferiorly to supply primerly the flexor
muscles of the forearm, the muscles and the skin of the hand.
•THE ULNAR NERVE:
It is the terminal branch of the brachial plexus. It passes through the arm into the forearm and hand.
In the forearm this nerve innervates the muscles laying at the medial side of the antebrachium. In the hand
most muscles and some skin are supplied by the ulnar nerve.
21. 3. THE POSTERIOR CORD
THE AXILLARY NERVE:
It is a large terminal branch of the posterior cord of the brachial plexus. It passes to the back of the arm
and supplies the shoulder joint, some of the shoulder girdl muscles and the skin of the shoulder region.
THE RADIAL NERVE:
is the other terminal branch of the posterior cord. It provides the major nerve supply to the extensors of the
upper limb and supplies the skin of the extensor region includung the back part of the hand.
The radial nerve runs backward, laying between the medial and the long heads of the triceps muscle and than
enters into the radial groove of the humerus. Than it runs downward to supply the forearm extensors.
26. BIBLIOGRAPHY
Gray’s Anatomy
Keith L. Moor: Clinically Oriented Anatomy
R.M.H.McMinn: Last’s Anatomy Regional and Applied
Sobotta Atlas of Human Anatomy, Vol. 2.
Werner Platzer: Color Atlas of Human Anatomy, Vol. 1. Locomotor System
http://wikipedia.com
Editor's Notes
Flexor and extensor muscles of the upper limb, blood supply and innervation of the upper limb
